Action Actuactor interrupting Motion Actuator
I guess you're using an armature rig for your character. In Blender it is possible to play different animations at the same time, if they don't requier the same bone of your armature. So for example doing an action with the arms while walking shouldn't be a problem.
Therefore you need to move one of your animations to another animation layer.

I'm not sure how you've set up your character, but I hope it helps!